1. Field of the Invention
The present invention relates to servers for differentiating among a plurality of terminals connected via a network, and more specifically relates to servers for identifying locations where each of the plurality of terminals is installed.
2. Description of the Background Art
Passenger transportation vehicles are often equipped with entertainment systems. The entertainment systems provided in the cabins of airplanes are called in-flight entertainment (IFE) systems, and various services are provided to passengers in the airplanes through such entertainment systems.
For example, with respect to contents such as movies and music, a passenger can watch images using a monitor terminal and listened to audio using a pair of headphones, which are allocated to all passenger seats. Generally, the monitor terminal is allocated on the back of the seat in front of a passenger seat, and the pair of headphones is connected to the armrest portion of the passenger seat.
In addition, services are provided to the passengers allowing control of an overhead reading light located above the seat to be turned on or off, calling a flight attendant, and calling another passenger via a telephone, by using a control panel or a remote control unit referred to as a handset which is included in the armrest portion of the seat and which is connected to the monitor terminal described above.
The handset operated by the passenger and the monitor terminal installed in each of the seats are connected to a server via a network. The server distributes the contents such as movies and music, notifies a flight attendant that he or she has been called, or performs the lighting control of the overhead reading lights.
With regard to the service of calling a flight attendant, when notifying a flight attendant that he or she has been called, it is necessary for the server to identify the seat at which the passenger is calling the flight attendant.
In addition, when turning the light of the overhead reading light, the server identifies the seat at which the passenger has operated the remote control unit or the control panel to turn on the overhead reading light allocated at a ceiling portion above the seat. Alternatively, when there is a malfunction in some of the terminals such as the remote control unit and the control panel and when passengers cannot perform any controls, it is necessary for the server to identify the terminals with the malfunction and immediately deal with the malfunction.
Therefore, in order to attain service functions as described above, it is necessary to identify the seat of a subject (passenger) who is requesting the service by operating the monitor terminal and the handset (or the location at which the operated monitor terminal is installed).
One conventional example of such a type of network system is disclosed in Japanese Laid-Open Patent Publication No. 2008-287302.
FIG. 9 shows a network system 90 in conventional art. In FIG. 9, the network system 90 includes an attendance management system 91, an L3 switch 92, an L2 switch 93, and a plurality of thin clients 94. As shown in FIG. 9, the attendance management system 91 includes an attendance management server, an IP segment DB, a switch DB, a switch location DB, and user information DB; and performs user authentication by using a personal authentication document 96.
When performing the user authentication using the personal authentication document 96, the attendance management server in the attendance management system 91 identifies the user who is using a computer (either one of the thin clients 94) by using unique user-identifiers that are stored.
Furthermore, the attendance management server acquires a MAC address of the computer used by the user based on an IP address of the computer, by using the L3 switch 92 which is capable of acquiring information from an address mapping table.
In addition, based on the acquired MAC address, the attendance management server acquires a port number of the L2 switch 93 connected to the computer used by the user.
As described above, the attendance management system 91 identifies the user's seat location based on information representing a relationship of connection locations of the L2 switch 93 and the respective thin clients 94, by referring to the DB stored in advance.
However, usage the above described conventional network system is limited to Ethernet (registered trademark) networks, and it has been necessary to use a specific network configuration. Therefore, the conventional network system has a problem where it does not correctly function in a network configuration such as, for example, FTTH (Fiber To The Home) service that uses GE-PON (Gigabit Ethernet (registered trademark) Passive Optical Network) method and includes repeaters whose port numbers cannot be identified.